Malignancies after hematopoietic cell transplantation for primary immune deficiencies: a report from the Center for International Blood and Marrow Transplant Research.

We describe the incidence of malignancy in patients with primary immunodeficiency disorders (PIDD) following hematopoietic cell transplantation (HCT). From the Center for International Blood and Marrow Transplant Research, 2266 PIDD patients who had undergone allogeneic HCT between 1968 and 2003 were identified. Patient, disease, and transplant factors for development of malignancy were examined and pathology reports for reported malignancies reviewed independently by a pathologist for confirmation. The incidence of malignancy was highest for Wiskott-Aldrich syndrome (3.3%), with an overall incidence of 2.3% for PIDD. Post-HCT malignancy was confirmed for 52 of 63 reported cases. Forty-five of 52 patients developed posttransplant lymphoproliferative disorders (PTLD) at a median of 3 months post-HCT. Of these, 26 had received T cell-depleted (TCD) bone marrow. Three patients who developed myelodysplastic syndrome had received TCD marrow and total body irradiation. Three patients developed a solid tumor. Patients with PIDD are at a relatively low risk of developing malignancies post-HCT compared with their historic risk of cancer. The most frequent malignancy or lymphoproliferative disorder was early-onset PTLD. As in other HCT recipients, TCD appears to correlate with PTLD development. Our results lend support to the hypothesis that immune reconstitution in PIDD following HCT leads to a decrease in cancer risk.